CN114647060A

CN114647060A - Imaging lens

Info

Publication number: CN114647060A
Application number: CN202011516284.1A
Authority: CN
Inventors: 李赞桦
Original assignee: Sintai Optical Shenzhen Co Ltd; Asia Optical Co Inc
Current assignee: Sintai Optical Shenzhen Co Ltd; Asia Optical Co Inc
Priority date: 2020-12-21
Filing date: 2020-12-21
Publication date: 2022-06-21
Anticipated expiration: 2040-12-21
Also published as: CN114647060B

Abstract

An imaging lens comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens, an eighth lens and a ninth lens. The first lens has refractive power and comprises a convex surface facing the object side. The second lens has a positive refractive power. The third lens has a negative refractive power. The fourth lens has positive refractive power. The fifth lens has a positive refractive power. The sixth lens has a positive refractive power. The seventh lens has a negative refractive power. The eighth lens element has refractive power and includes a convex surface facing the image side. The ninth lens element has refractive power and includes a convex surface facing the object side. The first lens element, the second lens element, the third lens element, the fourth lens element, the fifth lens element, the sixth lens element, the seventh lens element, the eighth lens element and the ninth lens element are sequentially disposed along an optical axis from an object side to an image side.

Description

Imaging lens

Technical Field

The invention relates to an imaging lens.

Background

The development trend of the existing imaging lens is continuously towards miniaturization development, and along with different application requirements, the existing imaging lens also needs to have the capabilities of small field of view, large aperture and high resolution, and the existing imaging lens cannot meet the existing requirements, and another imaging lens with a new framework is needed to meet the requirements of miniaturization, small field of view, large aperture and high resolution.

Disclosure of Invention

The present invention is directed to an imaging lens, and provides an imaging lens with short total length, small field of view, small aperture value, high resolution, and good optical performance, aiming at the defect that the imaging lens in the prior art cannot simultaneously satisfy the requirements of small field of view, large aperture and high resolution.

In order to solve the technical problem, the present invention provides an imaging lens including a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element, a sixth lens element, a seventh lens element, an eighth lens element, and a ninth lens element. The first lens has refractive power and comprises a convex surface facing the object side. The second lens has a positive refractive power. The third lens has a negative refractive power. The fourth lens has positive refractive power. The fifth lens has a positive refractive power. The sixth lens has a positive refractive power. The seventh lens has a negative refractive power. The eighth lens element has refractive power and includes a convex surface facing the image side. The ninth lens element has refractive power and includes a convex surface facing the object side. The first lens element, the second lens element, the third lens element, the fourth lens element, the fifth lens element, the sixth lens element, the seventh lens element, the eighth lens element and the ninth lens element are sequentially disposed along an optical axis from an object side to an image side.

The first lens element is a meniscus lens element with negative refractive power and may further include a concave surface facing the image side, the eighth lens element is a biconvex lens element with positive refractive power and may further include another convex surface facing the object side, and the ninth lens element is a biconvex lens element with positive refractive power and may further include another convex surface facing the image side.

The second lens element is a meniscus lens element and includes a convex surface facing the object side and a concave surface facing the image side, the fourth lens element is a biconvex lens element and includes a convex surface facing the object side and another convex surface facing the image side, the fifth lens element is a biconvex lens element and includes a convex surface facing the object side and another convex surface facing the image side, and the sixth lens element is a biconvex lens element and includes a convex surface facing the object side and another convex surface facing the image side.

The seventh lens element is a biconcave lens element having a concave surface facing the object side and another concave surface facing the image side.

The imaging lens of the invention may further include an aperture stop disposed between the fourth lens element and the fifth lens element.

The imaging lens meets the following conditions: TTL/f is more than or equal to 3.0 and less than or equal to 3.8; wherein, TTL is an axial distance from an object side surface of the first lens element to the image plane, and f is an effective focal length of the imaging lens.

The imaging lens meets the following conditions: f/f is more than or equal to 0.65₅Less than or equal to 0.8; wherein f is the effective focal length of the imaging lens, f₅Is the effective focal length of the fifth lens.

The imaging lens meets the following conditions: TTL/R is not less than 2.7₁₁Less than or equal to 3.0; wherein, TTL is the distance between the object side surface of the first lens element and the image plane on the optical axis, R₁₁Is the radius of curvature of the object-side surface of the first lens.

The imaging lens meets the following conditions: f is not less than 1.15₃₄/f₆₇Less than or equal to 1.80; wherein f is₃₄Is the combined effective focal length of the third lens and the fourth lens, f₆₇Is the combined effective focal length of the sixth lens and the seventh lens.

The imaging lens meets any one of the following conditions: vd₂<30；Vd₄>35; wherein, Vd₂Abbe number of the second lens, Vd₄Is the abbe number of the fourth lens.

The imaging lens has the following beneficial effects: the lens has the advantages of short total length, small field of view, small aperture value and high resolution, but still has good optical performance.

Drawings

In order to make the aforementioned and other objects, features and advantages of the present invention comprehensible, preferred embodiments accompanied with figures are described in detail below.

Fig. 1 is a lens arrangement diagram of a first embodiment of an imaging lens according to the present invention.

Fig. 2A is a Longitudinal Aberration (Longitudinal Aberration) diagram of the first embodiment of the imaging lens according to the present invention.

Fig. 2B is a Field Curvature (Field Curvature) diagram of the first embodiment of the imaging lens according to the present invention.

Fig. 2C is a Distortion (Distortion) diagram of the first embodiment of the imaging lens according to the present invention.

Fig. 2D is a Lateral chromatic aberration (lareal Color) diagram of the first embodiment of the imaging lens according to the present invention.

Fig. 2E is a Modulation Transfer Function (Modulation Transfer Function) diagram of the imaging lens according to the first embodiment of the invention.

Fig. 3 is a lens arrangement diagram of a second embodiment of an imaging lens according to the present invention.

Fig. 4A is a longitudinal aberration diagram of an imaging lens according to a second embodiment of the present invention.

Fig. 4B is a field curvature diagram of a second embodiment of an imaging lens according to the present invention.

Fig. 4C is a distortion diagram of the second embodiment of the imaging lens according to the present invention.

Fig. 4D is a lateral chromatic aberration diagram of the second embodiment of the imaging lens according to the present invention.

Fig. 4E is a diagram of a modulation transfer function of the imaging lens according to the second embodiment of the invention.

Fig. 5 is a lens arrangement diagram of a third embodiment of an imaging lens according to the present invention.

Fig. 6A is a longitudinal aberration diagram of the third embodiment of the imaging lens according to the present invention.

Fig. 6B is a curvature of field of the third embodiment of the imaging lens according to the present invention.

Fig. 6C is a distortion diagram of the third embodiment of the imaging lens according to the present invention.

Fig. 6D is a lateral chromatic aberration diagram of the third embodiment of the imaging lens according to the present invention.

Fig. 6E is a diagram of a modulation transfer function of an imaging lens according to a third embodiment of the invention.

Detailed Description

The present invention provides an imaging lens, including: the first lens has refractive power and comprises a convex surface facing the object side; the second lens has positive refractive power; the third lens has negative refractive power; the fourth lens has positive refractive power; the fifth lens has positive refractive power; the sixth lens has positive refractive power; the seventh lens has negative refractive power; the eighth lens element with refractive power has a convex surface facing the image side; the ninth lens has refractive power, and the ninth lens comprises a convex surface facing the object side; the first lens element, the second lens element, the third lens element, the fourth lens element, the fifth lens element, the sixth lens element, the seventh lens element, the eighth lens element and the ninth lens element are sequentially arranged along an optical axis from an object side to an image side.

Please refer to the following tables i, iii and v, wherein the tables i, iii and v are respectively the related parameter tables of the lenses according to the first to third embodiments of the imaging lens of the present invention.

Fig. 1, 3 and 5 are schematic lens configurations of the imaging lens according to the first, second and third embodiments of the present invention, respectively, wherein the first lenses L11, L21 and L31 are meniscus lenses with negative refractive power and are made of glass material, the object side surfaces S11, S21 and S31 are convex surfaces, the image side surfaces S12, S22 and S32 are concave surfaces, and the object side surfaces S11, S21 and S31 and the image side surfaces S12, S22 and S32 are spherical surfaces.

The second lenses L12, L22, and L32 are meniscus lenses having positive refractive power, and are made of glass material, and the object side surfaces S13, S23, and S33 are convex surfaces, the image side surfaces S14, S24, and S34 are concave surfaces, and the object side surfaces S13, S23, S33 and the image side surfaces S14, S24, and S34 are spherical surfaces.

The third lenses L13, L23, and L33 are biconcave lenses with negative refractive power, and are made of glass material, and the object side surfaces S15, S25, and S35 are concave surfaces, the image side surfaces S16, S26, and S36 are concave surfaces, and the object side surfaces S15, S25, S35 and the image side surfaces S16, S26, and S36 are all spherical surfaces.

The fourth lenses L14, L24, and L34 are biconvex lenses with positive refractive power, and are made of glass material, and the object side surfaces S17, S27, and S37 are convex surfaces, the image side surfaces S18, S28, and S38 are convex surfaces, and the object side surfaces S17, S27, S37 and the image side surfaces S18, S28, and S38 are all spherical surfaces.

The fifth lenses L15, L25, and L35 are biconvex lenses with positive refractive power, and are made of glass material, and the object side surfaces S110, S210, and S310 are convex surfaces, the image side surfaces S111, S211, and S311 are convex surfaces, and the object side surfaces S110, S210, and S310 and the image side surfaces S111, S211, and S311 are spherical surfaces.

The sixth lenses L16, L26, and L36 are biconvex lenses with positive refractive power, and are made of glass, wherein the object-side surfaces S112, S212, and S312 are convex surfaces, the image-side surfaces S113, S213, and S313 are convex surfaces, and the object-side surfaces S112, S212, and S312 and the image-side surfaces S113, S213, and S313 are spherical surfaces.

The seventh lenses L17, L27, and L37 are biconcave lenses with negative refractive power, and are made of glass material, and the object side surfaces S114, S214, and S314 are concave surfaces, the image side surfaces S115, S215, and S315 are concave surfaces, and the object side surfaces S114, S214, and S314 and the image side surfaces S115, S215, and S315 are spherical surfaces.

The eighth lenses L18, L28, and L38 are biconvex lenses having positive refractive power, and are made of glass, and the object-side surfaces S116, S216, and S316 are convex surfaces, the image-side surfaces S117, S217, and S317 are convex surfaces, and the object-side surfaces S116, S216, and S316 and the image-side surfaces S117, S217, and S317 are spherical surfaces.

The ninth lenses L19, L29 and L39 are biconvex lenses with positive refractive power, made of glass, and have convex object-side surfaces S118, S218 and S318, convex image-side surfaces S119, S219 and S319, and spherical object-side surfaces S118, S218 and S318 and spherical image-side surfaces S119, S219 and S319.

In addition, the

imaging lenses

1, 2, 3 at least satisfy one of the following conditions:

3.0≤TTL/f≤3.8； (1)

0.65≤f/f₅≤0.8； (2)

2.7≤TTL/R₁₁≤3.0； (3)

1.15≤f₃₄/f₆₇≤1.80； (4)

Vd₂<30； (5)

Vd₄>35； (6)

wherein, TTL is the first embodiment to the third embodiment, and the object side surfaces S11, S21, S31 of the first lenses L11, L21, L31 are respectively to the imaging surfaces IMA1, IThe distances between MA2 and IMA3 on optical axes OA1, OA2 and OA3, f is the effective focal length of the

imaging lenses

1, 2 and 3 in the first to third embodiments, and f is₅Effective focal lengths, f, of the fifth lenses L15, L25, L35 in the first to third embodiments₃₄The effective focal lengths of the third lenses L13, L23, L33 in combination with the fourth lenses L14, L24, L34, respectively, f₆₇The combined effective focal lengths of the sixth lenses L16, L26, L36 and the seventh lenses L17, L27, L37, R being the first to third embodiments, respectively₁₁The object side surfaces S11, S21, S31 of the first lenses L11, L21, L31 have the radius of curvature Vd in the first to third embodiments₂Abbe's number, Vd, of the second lenses L12, L22, L32 in the first to third embodiments₄Abbe numbers of the fourth lenses L14, L24, and L34 in the first to third embodiments. The

imaging lenses

1, 2 and 3 can effectively shorten the total length of the lenses, effectively reduce the aperture value, effectively improve the resolution, effectively correct the aberration and effectively correct the chromatic aberration.

A first embodiment of the imaging lens of the present invention will now be described in detail. Referring to fig. 1, the imaging lens 1 includes, in order from an object side to an image side along an optical axis OA1, a first lens element L11, a second lens element L12, a third lens element L13, a fourth lens element L14, an aperture stop ST1, a fifth lens element L15, a sixth lens element L16, a seventh lens element L17, an eighth lens element L18, a ninth lens element L19, a filter OF1, and a protective glass CG 1. In imaging, light from the object side is finally imaged on the imaging surface IMA 1. According to [ embodiments ] the first to eleventh paragraphs, wherein:

the filter OF1 has an object-side surface S120 and an image-side surface S121 both being planar; the object-side surface S122 and the image-side surface S123 of the protective glass CG1 are both planar;

by using the design that the lens, the aperture ST1 at least satisfy one of the conditions (1) to (6), the imaging lens 1 can effectively shorten the total lens length, effectively reduce the aperture value, effectively improve the resolution, effectively correct the aberration, and effectively correct the chromatic aberration.

Table one is a table of relevant parameters of each lens of the imaging lens 1 in fig. 1.

Watch 1

The second table shows the related parameter values of the imaging lens 1 and the calculated values corresponding to the conditions (1) to (6) in the first embodiment, and it can be seen from the second table that the imaging lens 1 in the first embodiment can satisfy the requirements of the conditions (1) to (6).

Watch two

f₃₄	-62.71mm	f₆₇	-38.15mm
						TTL/f	3.61	f/f₅	0.69	TTL/R₁₁	2.97
f₃₄/f₆₇	1.64	Vd₂	20.88	Vd₄	40.87

In addition, the optical performance of the imaging lens 1 of the first embodiment can also meet the requirement, and as can be seen from fig. 2A, the longitudinal aberration of the imaging lens 1 of the first embodiment is between-0.01 mm and 0.03 mm. As can be seen from fig. 2B, the curvature of field of the imaging lens 1 of the first embodiment is between-0.02 mm and 0.03 mm. As can be seen from fig. 2C, the distortion of the imaging lens 1 of the first embodiment is between-8% and 0%. As can be seen from fig. 2D, the imaging lens 1 of the first embodiment has a lateral chromatic aberration between-0.5 μm and 2.5 μm. As shown in fig. 2E, the modulation transfer function value of the imaging lens 1 of the first embodiment is between 0.52 and 1.0.

It is obvious that the imaging lens 1 of the first embodiment can effectively correct longitudinal aberration, curvature of field, distortion and transverse chromatic aberration, and the lens resolution can also meet the requirements, thereby obtaining better optical performance.

Referring to fig. 3, the imaging lens 2 includes, in order from an object side to an image side along an optical axis OA2, a first lens element L21, a second lens element L22, a third lens element L23, a fourth lens element L24, an aperture stop ST2, a fifth lens element L25, a sixth lens element L26, a seventh lens element L27, an eighth lens element L28, a ninth lens element L29, a filter OF2, and a protective glass CG 2. In imaging, light from the object side is finally imaged on the imaging surface IMA 2. According to [ embodiments ] the first to eleventh paragraphs, wherein:

the optical filter OF2 has an object-side surface S220 and an image-side surface S221 both being flat; the object side surface S222 and the image side surface S223 of the protective glass CG2 are both planar;

by using the design that the lens, the aperture ST2 at least satisfy one of the conditions (1) to (6), the imaging lens 2 can effectively shorten the total lens length, effectively reduce the aperture value, effectively improve the resolution, effectively correct the aberration, and effectively correct the chromatic aberration.

Table three is a table of the relevant parameters of each lens of the imaging lens 2 in fig. 3.

Watch III

Table four shows the values of the relevant parameters of the imaging lens 2 of the second embodiment and the calculated values corresponding to the conditions (1) to (6), and it can be seen that the imaging lens 2 of the second embodiment can satisfy the requirements of the conditions (1) to (6).

Watch four

f₃₄	-48.93mm	f₆₇	-41.38mm
						TTL/f	3.09	f/f₅	0.80	TTL/R₁₁	2.95
f₃₄/f₆₇	1.18	Vd₂	20.88	Vd₄	40.87

In addition, the optical performance of the imaging lens 2 of the second embodiment can also meet the requirement, and as can be seen from fig. 4A, the longitudinal aberration of the imaging lens 2 of the second embodiment is between-0.02 mm and 0.03 mm. As can be seen from fig. 4B, the curvature of field of the imaging lens 2 of the second embodiment is between-0.02 mm and 0.03 mm. As can be seen from fig. 4C, the distortion of the imaging lens 2 of the second embodiment is between-6% and 0%. As can be seen from fig. 4D, the lateral chromatic aberration of the imaging lens 2 of the second embodiment is between 0 μm and 3.0 μm. As shown in fig. 4E, the modulation transfer function value of the imaging lens 2 of the second embodiment is between 0.56 and 1.0. .

It is obvious that the longitudinal aberration, curvature of field, distortion and lateral chromatic aberration of the imaging lens 2 of the second embodiment can be effectively corrected, and the lens resolution can also meet the requirements, thereby obtaining better optical performance.

Referring to fig. 5, the imaging lens assembly 3 includes, in order from an object side to an image side along an optical axis OA3, a first lens element L31, a second lens element L32, a third lens element L33, a fourth lens element L34, an aperture stop ST3, a fifth lens element L35, a sixth lens element L36, a seventh lens element L37, an eighth lens element L38, a ninth lens element L39, a filter OF3, and a protective glass CG 3. In imaging, light from the object side is finally imaged on the imaging surface IMA 3. According to [ embodiments ] the first to eleventh paragraphs, wherein:

the filter OF3 has an object-side surface S320 and an image-side surface S321 both being planar; the object-side surface S322 and the image-side surface S323 of the cover glass CG3 are both planar;

by using the design that the lens, the aperture ST3 at least satisfy one of the conditions (1) to (6), the imaging lens 3 can effectively shorten the total lens length, effectively reduce the aperture value, effectively improve the resolution, effectively correct the aberration, and effectively correct the chromatic aberration.

Table five is a table of relevant parameters of each lens of the imaging lens 3 in fig. 5.

Watch five

Table six shows the related parameter values of the imaging lens 3 of the third embodiment and the calculated values corresponding to the conditions (1) to (6), and it can be seen from table six that the imaging lens 3 of the third embodiment can satisfy the requirements of the conditions (1) to (6).

Watch six

f₃₄	-62.78mm	f₆₇	-34.92mm
						TTL/f	3.40	f/f₅	0.75	TTL/R₁₁	2.80
f₃₄/f₆₇	1.80	Vd₂	20.88	Vd₄	40.87

In addition, the optical performance of the imaging lens 3 of the third embodiment can also meet the requirement, and as can be seen from fig. 6A, the longitudinal aberration of the imaging lens 3 of the third embodiment is between-0.01 mm and 0.03 mm. As can be seen from fig. 6B, the curvature of field of the imaging lens 3 of the third embodiment is between-0.02 mm and 0.04 mm. As can be seen from fig. 6C, the distortion of the imaging lens 3 of the third embodiment is between-6% and 0%. As can be seen from fig. 6D, the imaging lens 3 of the third embodiment has a lateral chromatic aberration between 0 μm and 2.5 μm. As shown in fig. 6E, the modulation transfer function value of the imaging lens 3 of the third embodiment is between 0.59 and 1.0.

It is obvious that the longitudinal aberration, curvature of field, distortion and lateral chromatic aberration of the imaging lens 3 of the third embodiment can be effectively corrected, and the lens resolution can also meet the requirements, thereby obtaining better optical performance.

Although the present invention has been described with reference to the above embodiments, it should be understood that various changes and modifications may be made therein by those skilled in the art without departing from the spirit and scope of the invention.

Claims

1. An imaging lens, characterized by comprising:

the first lens has refractive power and comprises a convex surface facing the object side;

the second lens has positive refractive power;

the third lens has negative refractive power;

the fourth lens has positive refractive power;

the fifth lens has positive refractive power;

the sixth lens has positive refractive power;

the seventh lens has negative refractive power;

the eighth lens element with refractive power has a convex surface facing the image side; and

the ninth lens has refractive power, and the ninth lens comprises a convex surface facing the object side;

the first lens element, the second lens element, the third lens element, the fourth lens element, the fifth lens element, the sixth lens element, the seventh lens element, the eighth lens element and the ninth lens element are sequentially disposed along an optical axis from the object side to the image side.

2. The imaging lens of claim 1, characterized in that:

the first lens has negative refractive power;

the eighth lens has positive refractive power; and

the ninth lens has a positive refractive power.

3. The imaging lens of claim 2, wherein:

the first lens element is a meniscus lens element and further includes a concave surface facing the image side;

the eighth lens element is a biconvex lens element, and further includes another convex surface facing the object side; and

the ninth lens element is a biconvex lens element and further includes another convex surface facing the image side.

4. The imaging lens assembly of claim 1, wherein the second lens element is a meniscus lens element and includes a convex surface facing the object side and a concave surface facing the image side.

5. The imaging lens assembly of claim 1, wherein the third lens element is a bi-concave lens element and includes a concave surface facing the object side and another concave surface facing the image side.

6. The imaging lens of claim 1,

the fourth lens element is a biconvex lens element, and has a convex surface facing the object side and another convex surface facing the image side; and

the fifth lens element is a biconvex lens element and has a convex surface facing the object side and another convex surface facing the image side.

7. The imaging lens assembly as claimed in claim 1, wherein the sixth lens element is a biconvex lens element and includes a convex surface facing the object side and another convex surface facing the image side.

8. The imaging lens assembly of claim 1, wherein the seventh lens element is a bi-concave lens element and includes a concave surface facing the object side and another concave surface facing the image side.

9. The imaging lens assembly of claim 1, further comprising an aperture stop disposed between the fourth lens element and the fifth lens element.

10. The imaging lens according to any one of claims 1 to 9, characterized in that the imaging lens satisfies at least one of the following conditions:

3.0≤TTL/f≤3.8；

2.7≤TTL/R₁₁≤3.0；

0.65≤f/f₅≤0.8；

1.15≤f₃₄/f₆₇≤1.80；

Vd₂<30；

Vd₄>35；

wherein, TTL is the distance between the object side surface of the first lens and the imaging surface on the optical axis, f is the effective focal length of the imaging lens, R₁₁Is the radius of curvature of the object-side surface of the first lens, f₅Is the effective focal length of the fifth lens, f₃₄Is the combined effective focal length of the third lens and the fourth lens, f₆₇Is the combined effective focal length, Vd, of the sixth lens and the seventh lens₂Is Abbe number, Vd, of the second lens₄Is the abbe number of the fourth lens.